This invention relates to a loudspeaker horn, and in particular (although not exclusively) to a a low to mid frequency loudspeaker horn for public address, theatre and band uses.
In applications where it is necessary to provide low to mid frequency sound at high volumes, such as in public address, theatre and band uses, it has been a problem to provide a sound output having an even dispersion over the entire frequency range in the vertical and, particularly, in the horizontal plane. Various types of horn enclosures have been used to control the sound emitted from the loudspeaker cone, and in particular it has been common to use exponential horns and hyperbolic horns. The exponential horn lacks a control throat in the horn and gives a very high dispersion of sound at low frequencies while being very directional at high frequencies. Hyperbolic horns also have very directional high frequencies and tend to spit out the sound rather than dispersing the sound uniformly in a pleasant manner. To overcome these difficulties with the highly directional sound emitted from exponential and hyperbolic horns toward the upper end of their range, it has been common to use the low frequency units with a relatively low crossover frequency, for example five hundred, eight hundred or twelve hundred Hz, so that the mid-range frequencies are handled by the high frequency unit. This has the attendant disadvantage that the high frequency unit must be much larger and must have a higher power handling capacity than would otherwise be required with a higher crossover frequency. Alternatively, because the high frequency unit is of a light construction to give the required high frequency response, it tends to burn out very quickly from having to handle the comparatively low mid-range frequency imposed by the crossover.